First set up your current phone numbers through Loxo's SIP-enabled power calling system. With Loxo's built-in phone system you can check your voicemails within the app. This feature is only available for SIP-enabled accounts.
A voicemail greeting can be set in Settings > Phone:
If the user misses the call, or the line is busy or disconnected, the caller will be directed to voicemail. A Loxo user will get an email notification whenever they receive a voicemail and their voicemails can be checked by going to the gear icon > Voicemail: